Plastic parts have been proliferating the underhood environment for mass and cost savings. Noise control can become an issue with these parts. A noise cover can solve these problems. Data in this paper demonstrate the acoustical absorption capabilities of a nylon 6 / foam composite cover. Using these data, it becomes possible to predict the amount of attenuation using various thickness' of open-cell foam and nylon 6. The three most important factors to use when designing a new cover are acoustical absorption, transmission loss, and percentage of acoustical leakage around the cover or barrier.